Performance evaluation of adaptive aperture's static and dynamic collimation in a compact pencil beam scanning proton therapy system: A dosimetric comparison study for multiple disease sites
This study evaluates dosimetric performance of SA and DA for different disease sites. This study includes 5 disease sites (brain, head and neck (HN), partial breast, lung, and prostate), and 8 patients for each. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 2, 2020 Category: Radiology Authors: Hardev S. Grewal, Salahuddin Ahmad, Hosang Jin Source Type: research

Comparative evaluation of treatment plan quality for a prototype biology-guided radiotherapy system in the treatment of nasopharyngeal carcinoma
We aimed to compare prototype treatment plans for a new biology-guided radiotherapy (BgRT) machine in its intensity-modulated radiation therapy (IMRT) mode with those using existing IMRT delivery techniques in treatment of nasopharyngeal carcinoma (NPC). We retrospectively selected ten previous NPC patients treated in 33 fractions according to the NRG-HN001 treatment protocol. Three treatment plans were generated for each patient: a helical tomotherapy (HT) plan with a 2.5-cm jaw, a volumetric modulated arc therapy (VMAT) plan using 2 to 4 6-MV arc fields, and a prototype IMRT plan for a new BgRT system which uses a 6-MV p...
Source: Medical Dosimetry - November 30, 2020 Category: Radiology Authors: Chunhui Han, Angela J. Da Silva, Jieming Liang, Christopher Wohlers, Cal Huntzinger, John P. Neylon, Dongsu Du, Jeffrey Y.C. Wong, An Liu Source Type: research

Investigating the utilization of beam-specific apertures for the intensity-modulated proton therapy (IMPT) head and neck cancer plans
Intensity-modulated proton therapy (IMPT) planning for the head and neck (HN) cancer often requires the use of the range shifter, which can increase the lateral penumbrae of the pencil proton beam in the patient, thus leading to an increase in unnecessary dose to the organs at risks (OARs) in proximity to the target volumes. The primary goal of the current study was to investigate the dosimetric benefits of utilizing beam-specific apertures for the IMPT HN cancer plans. The current retrospective study included computed tomography datasets of 10 unilateral HN cancer patients. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 24, 2020 Category: Radiology Authors: Suresh Rana, Mark Storey, Noufal Manthala Padannayil, Dayananda Sharma Shamurailatpam, Jaafar Bennouna, Jerry George, John Chang Source Type: research

The feasibility and efficacy of new SBRT technique HyperArc for recurrent nasopharyngeal carcinoma: noncoplanar cone-based robotic system vs. noncoplanar high-definition MLC based Linac system
The purpose of this study was to evaluate the feasibility and efficacy of HyperArc (HA) for recurrent nasopharyngeal cancer (NPC) by comparing it with the CyberKnife system (CK). Fifteen patients with recurrent nasopharyngeal cancer who were treated using the noncoplanar cone-based robotic CK system were enrolled. CK was delivered with a median dose of 37.5 Gy in 5 fractions. The delivered CK treatment plans were the sources for the corresponding homogeneous HA (HA-H) and inhomogeneous HA (HA-IH) plans. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 15, 2020 Category: Radiology Authors: Hsiu-Wen Ho, Ching-Chieh Yang, Hsiu-Man Lin, Hsiao-Yun Chen, Chun-Chiao Huang, Shih-Chang Wang, Yu-Wei Lin Source Type: research

Methods to optimize conformal dynamic arcs in radiation therapy treatment planning
Conformal Dynamic Arcs (CDA) can provide a useful alternative in certain clinical situations which require a higher level of 3-dimensional (3D) conformation than shaped static fields but for which modulated fields (fixed or arc) are inappropriate. Due to lack of modulation, the quality of the dose distribution produced by a CDA is highly dependent on the specific patient geometry. The ideal geometry for a CDA, in terms of achievable conformation and uniformity, is a spherical target perfectly centered in a cylindrical medium or body and utilizing a full 360 degree of rotation. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 7, 2020 Category: Radiology Authors: Caroline Kendra, Lon Marsh, Elaine Bogner, Benjamin Gielda Source Type: research

Characterization of 3D-printed bolus produced at different printing parameters
We aimed to analyze the effects of printing parameters on characterization of three-dimensional (3D) printed bolus used in external beam radiotherapy. Two sets of measurements were performed to investigate the dosimetric and physical characterization of 3D-printed bolus at different printing parameters. In the first step, boluses were produced at different infill-percentages, infill-patterns and printing directions. Two-dimensional (2D) dose measurements were performed in Elekta Versa HD linear accelerator using 6 MV photon energy. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 7, 2020 Category: Radiology Authors: Fatih Biltekin, Gozde Yazici, Gokhan Ozyigit Source Type: research

Investigation of approaches for internal target volume definition using 4-dimensional computed tomography in stereotactic body radiotherapy of lung cancer
The present study was undertaken to investigate the suitability of alternative internal target volume (ITV) delineation strategies based on maximum intensity projection (MIP), average intensity projection (AIP), 2 extreme phases and 4 phases images relative to the ITV10phase in stereotactic body radiation therapy (SBRT) for lung cancer. The 4-dimensional computed tomography (4DCT) data of 15 lung cancer patients treated with SBRT in our clinic were used. Five different ITVs were generated as follows: merging GTVs from 10 phases (ITV10Phase); merging GTVs from 2 extreme phases (0%, 50%) (ITV2Phase); merging GTVs from 4 phas...
Source: Medical Dosimetry - October 27, 2020 Category: Radiology Authors: Canan Koksal, Nazmiye Donmez Kesen, Murat Okutan, Sule Karaman, Nergiz Dagoglu Sakin, Hatice Bilge Source Type: research

Verification using in vivo optically stimulated luminescent dosimetry of the predicted skin surface dose in patients receiving postmastectomy radiotherapy
The purpose of this study was to evaluate whether dose to the skin surface underneath bolus, was accurately predicted by a 3D treatment planning system (TPS) in patients receiving 50 Gy/25# postmastectomy radiotherapy (PMRT) using optically stimulated luminescent dosimetry (OSLD) for verification. In vivo dosimetry using OSLDs was performed in 20 consecutive patients receiving PMRT. An array of 9 OSLDs were applied to the chest wall or neobreast in a grid arrangement. Dosimetry data were recorded on 3 separate treatment fractions, averaged, and extrapolated to 25 fractions. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 24, 2020 Category: Radiology Authors: Johnathon R. Wake, Feng Qin Chen, Simon Ashworth, Karen Byth, Wei Wang, Kirsty E. Stuart Source Type: research

A novel approach to embed eye shields in customized bolus on nasal dorsum treatment for electron radiotherapy
We aim to demonstrate the unique use of embedded lead eye shields in an electron wax bolus when treating the nasal dorsum. A patient presented to the clinic with squamous cell carcinoma of the nasal dorsum requiring treatment with en face electrons. A 3D customized wax bolus was designed and imported into the treatment planning system (TPS) to calculate the dose distribution. Due to high lens dose, the bolus was customized further to create 2 milled open slots in the wax, over the lens of eye, to allow lead sheets totaling 4 mm to be slid into the wax. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 21, 2020 Category: Radiology Authors: Xiao Wang, Beth Swann, Meral Reyhan, Ning J. Yue, Rachana Singh, Michael G. McKenna Source Type: research

Reduction of cardiac dose using respiratory-gated MR-linac plans for gastro-esophageal junction cancer
Treatment of locally advanced adenocarcinoma of the gastroesophageal junction (GEJ) with chemoradiation may be associated with high rates of symptomatic cardiac toxicity. Large margins are typically required to ensure coverage of GEJ tumors with free-breathing volumetric modulated arc therapy (VMAT) radiotherapy. The purpose of this study is to determine whether treatment with tighter margins enabled by maximum-inhalation breath hold (MIBH)-gated intensity modulated radiation therapy (IMRT) on an integrated MRI-linear accelerator system (MR-linac) can decrease radiation doses to the heart and cardiac substructures. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 20, 2020 Category: Radiology Authors: Sangjune Laurence Lee, Peter Mahler, Stephanie Olson, Jacob S. Witt, Hima Bindu Musunuru, Victoria Rajamanickam, Michael F. Bassetti, Poonam Yadav Source Type: research

Assessing tumor centrality in lung stereotactic ablative body radiotherapy (SABR): the effects of variations in bronchial tree delineation and potential for automated methods
Accurate delineation of the proximal bronchial tree (PBT) is crucial for appropriate assessment of lung tumor centrality and choice of Stereotactic Ablative Body Radiotherapy (SABR) dose prescription. Here, we investigate variabilities in manual PBT delineation and their potential to influence assessing lesion centrality. A fully automatic, intensity-based tool for PBT contouring and measuring distance to the target is also described. This retrospective analysis included a total of 61 patients treated with lung SABR. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 13, 2020 Category: Radiology Authors: Wsam Ghandourh, Jason Dowling, Phillip Chlap, Andrew Oar, Susannah Jacob, Vikneswary Batumalai, Lois Holloway Source Type: research

Continuous positive airway pressure with deep inspiration breath hold in left-sided breast radiation therapy
A dosimetric study to evaluate the use of continuous positive airway pressure (CPAP), with free-breathing (CPAP-FB) or with deep inspiration breath hold (DIBH-CPAP) an adjunct and alternative to DIBH to reduce heart and lung dose in the radiation therapy (RT) of breast cancer planned for left side RT with regional nodes and internal mammary. A retrospective analysis of 10 left-sided breast cancer patients whose heart or lung dose constraints were not met after RT planning based on FB or DIBH simulations and were referred for CPAP-based planning. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 1, 2020 Category: Radiology Authors: Jensen Reckhow, Orit Kaidar-Person, Merav A. Ben-David, Anna Ostrovski, Dina Ilinsky, Jeffrey Goldstein, Zvi Symon, Shira Galper Source Type: research

Dosimetric evaluation of image-guided radiation therapy for prostate cancer
Prostate cancer is the most common malignancy in North American males and the second leading cause of cancer death. External beam radiation therapy plays an important role in the clinical management of prostate cancer of various stages. Currently, image-guided target localization for intensity-modulated radiation therapy (IMRT) of prostate cancer has become a routine procedure, and plays an essential role in dose escalation and hypo-fractionation clinical trials, especially for those that employ stereotactic body radiation therapy (SBRT) techniques. (Source: Medical Dosimetry)
Source: Medical Dosimetry - October 1, 2020 Category: Radiology Authors: Guoping Shan, Wei Hu, Lili Chen, Robert A Price, C-M Charlie Ma Source Type: research

The robustness of VMAT radiotherapy for breast cancer with tissue deformations
To investigate the near-surface doses and target coverage in modulated arc radiotherapy (RT) of the breast or chest wall in two treatment planning systems (TPS) in the presence of soft tissue deformations. This retrospective study consisted of 10 breast cancer patients with axillary lymph node inclusion. For each case, five RT plans were created: (1) tangential 3D conformal field-in-field (FinF) technique; (2) 200 ° to 240° arcs with optimization bolus (OB) in Eclipse (EB); (3) 243° to 250° arcs with an 8-mm OB in Monaco (MB); (4) 243° to 250° arcs with automatic skin flash tool (ASF) in Monaco TPS ...
Source: Medical Dosimetry - September 25, 2020 Category: Radiology Authors: Maija Rossi, Tuomas Vir én, Janne Heikkilä, Jan Seppälä, Eeva Boman Tags: Dosimetry Contribution Source Type: research

Efficacy of MLC based cobalt-60 plans: A DVH comparison and analysis with 6 MV plans
The purpose of this study was to compare 3D treatment plans implemented using 6 MV Linac with a retrofitted multileaf collimator (MLC) based cobalt-60 plans. In this retrospective study, DVH analysis was used to compare homogeneity of dose within the target and the dose received by critical organs. A prototype MLC designed and developed as a retrofit to current cobalt-60 teletherapy machines with a dedicated 3D treatment planning system was used. Cases representing 5 tumor sites like head& neck, glottis, lung, gall bladder, stomach were taken for the study, which were planned using Eclipse treatment planning system and...
Source: Medical Dosimetry - September 24, 2020 Category: Radiology Authors: Akula Roopa Rani, Komanduri Ayyangar, A.R. Reddy, Ayyalasomayajula Anil Kumar, Pal Reddy Yadagiri Reddy Source Type: research

New method for measurement of chest surface motion in lung cancer patients: Quantification using a technique of deformable image registration
The purpose of this study was to measure the motion of the chest surface during breath-holding treatment for lung cancer using deformable image registration (DIR). Forty non –small-cell lung cancer patients treated with breath-holding stereotactic body radiation therapy were retrospectively examined. First, intensity-based DIR between 2 breath-holding computed tomography (CT) images was performed. Subsequently, deformation vector field (DVF) for all dimensions (left-r ight, anterior-posterior, and superior-inferior) was calculated from the result. (Source: Medical Dosimetry)
Source: Medical Dosimetry - September 20, 2020 Category: Radiology Authors: Masahide Saito, Naoki Sano, Kengo Kuriyama, Takafumi Komiyama, Kan Marino, Shinichi Aoki, Yoshiyasu Maehata, Hidekazu Suzuki, Koji Ueda, Hiroshi Onishi Source Type: research

Automatic feathering algorithm for VMAT craniospinal irradiation: A comprehensive comparison with other VMAT planning strategies
In this study, a treatment planning system-integrated method, named automatic feathering (AF) algorithm, was compared against other volumetric-modulated arc therapy strategies. (Source: Medical Dosimetry)
Source: Medical Dosimetry - September 19, 2020 Category: Radiology Authors: Michele Maddalo, Giovanna Benecchi, Luisa Altabella, Caterina Ghetti, Nunziata D'Abbiero Source Type: research

Dose simulations of an early 20th century kilovoltage pneumonia radiotherapy technique performed with a modern fluoroscope
To simulate an early 20th century viral pneumonia radiotherapy treatment using modern fluoroscopy and evaluated it according to current dose guidelines. Monte Carlo was used to assess the dose distribution on an anthropomorphic phantom. Critical organs were: skin, breasts, esophagus, ribs, vertebrae, heart, thymus, and spinal cord. A 100 kVp beam with 3 mm Al HVL, 25  × 25 cm2 posterior-anterior (PA) field and 50 cm source-to-surface distance were simulated. Simulations had a resolution of 0.4 × 0.4 × 0.06 cm3 and a 6% uncertainty. (Source: Medical Dosimetry)
Source: Medical Dosimetry - September 17, 2020 Category: Radiology Authors: Dante Roa, Harry Moyses, Stephanie Leon, Barbara Hamrick, Gustavo R. Sarria, Benjamin Li, Toshiki Tajima, Ales Necas, Carmen Guzman, Oliver Paucar, Alberto Gonzales, Roger Challco, Modesto Montoya, Zintia Arqque, Andres Gonzales, Jimmy Hernandez, Johnny D Source Type: research

Radiotherapy for the prophylaxis of heterotopic ossification after total hip arthroplasty: A systematic review and meta-analysis of randomized controlled trails
Heterotopic ossification (HO) refers to the formation of lamellar bone in soft tissues and is a significant complication after total hip arthroplasty (THA). Radiotherapy has been proven as an effective prophylaxis especially for those patients with high risk of HO after THA. However the dose, timing, and frequency of radiation have yet to be determined. To compare HO progressions with different radiotherapy strategies and explore an optimal radiation option. We systematically searched PubMed, Embase, and Cochrane Library for randomized controlled trails (through December 1, 2019; no language restrictions) collecting patien...
Source: Medical Dosimetry - September 10, 2020 Category: Radiology Authors: Zheng-Hao Hu, Wang Chen, Jian-Ning Sun, Ye Zhang, Yu Zhang, Xiang-Yang Chen, Shuo Feng Source Type: research

Patient-specific radiotherapy quality assurance for estimating actual treatment dose
This study aimed to evaluate the optimal method for planning computed tomography (CT) for prostate cancer radiotherapy to avoid a dose difference of ≥3% between the actual and planned treatments using multiple acquisition planning CT (MPCT). We calculated the 3-dimensional (3D) displacement error between the pelvic bone and matching fiducial marker on MPCT and cone-beam CT scans of 25 patients who underwent prostate volumetric-modulated arc th erapy for prostate cancer. The correlation of the 3D displacement error and the dose difference between planned and actual treatments was calculated using least squares second-ord...
Source: Medical Dosimetry - September 10, 2020 Category: Radiology Authors: Yoshinori Tanabe, Takayuki Ishida, Hidetoshi Eto, Tatsuhiro Sera, Yuki Emoto, Mototsugu Shimokawa Source Type: research

Dosimetric assessment of bolus for postmastectomy radiotherapy
There remains wide variation in the use of chest wall boluses for postmastectomy radiotherapy, which may result from the need for 2 treatment plans with the commonly used half-time tissue-equivalent 5-mm-thick bolus to achieve a full surface dose. To establish a bolus method requiring one treatment plan, we assessed the surface dose of a thinner daily bolus for all treatment fractions and compared it against the half-time 5-mm-thick bolus. In this basic study, we specifically investigated dosage achieved when using the following: (1) the existing bolus protocol, a half-time 5-mm-thick tissue-equivalent Clearfit bolus (Fuji...
Source: Medical Dosimetry - September 1, 2020 Category: Radiology Authors: Terufumi Kawamoto, Naoto Shikama, Chie Kurokawa, Naoya Hara, Masaki Oshima, Keisuke Sasai Source Type: research

Approach to account for the impact of dental artifacts on VMAT dose distributions when using automated treatment planning
(Source: Medical Dosimetry)
Source: Medical Dosimetry - August 31, 2020 Category: Radiology Source Type: research

Left anterior descending artery avoidance in patients receiving breast irradiation
Dose to the left anterior descending artery (LAD) may be significant in patients receiving left-sided irradiation for breast cancer. We investigated if prospective contouring and avoidance of the LAD during treatment planning were associated with lower LAD dose. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 29, 2020 Category: Radiology Authors: Aleksander Vayntraub, Thomas J. Quinn, Andrew B. Thompson, Peter Y. Chen, Gregory S. Gustafson, Maha S. Jawad, Joshua T. Dilworth Source Type: research

Assessment of robustness of institutional applied clinical target volume (CTV) to planning target volume (PTV) margin in cervical cancer using biological models
The aim of this study is to investigate the robustness of our institutionally applied clinical target volume (CTV)-to-planning target volume (PTV) margins in cervical cancer patients in terms of an equivalent uniform dose (EUD) based on tumor control probability (TCP). We simulated target motion using 25 IMRT cervical cancer plans to demonstrate the effect of geometrical uncertainties on the EUD and TCP. The different components of the total geometrical uncertainties budget were estimated. The biological effects were compared by calculating the EUDs from the trial DVHs. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 28, 2020 Category: Radiology Authors: Milovan Savanovi ć, Bojan Štrbac Source Type: research

Ablative Re-irradiation of Inoperable Pancreatic Cancer: A Case Study of Gastrointestinal Sparing through MR-guided Online Adaptive Radiotherapy
(Source: Medical Dosimetry)
Source: Medical Dosimetry - August 24, 2020 Category: Radiology Source Type: research

Radiosurgery treatment planning using conformal arc informed volumetric modulated arc therapy
In this study we introduce, describe, and evaluate a treatment planning technique called Conformal Arc Informed VMAT (CAVMAT), which aims to reduce the dose to healthy tissue while generating highly conformal treatment plans. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 13, 2020 Category: Radiology Authors: William M. Giles, Edward T. Cullom, Obed A.-O. Laryea, Ahmad Nobah, Victor G.L. Alves, Fang-Fang Yin, John P. Kirkpatrick, Justus D. Adamson Source Type: research

A service line approach: Using whiteboard analytics to improve time efficiency in radiation oncology
The purpose of this study was to develop and implement a custom-designed electronic workflow management tool created by Medlever, Inc, in order to improve efficiency, leverage interoperability and maximize overall labor resources. Administrators and clinicians from five Banner MD Anderson Cancer Center, Department of Radiation Oncology clinics utilized Medlever, Inc. to track and analyze clinical workflow. Real-time data were collected for the duration of 3 months. Time and process data were compared month-to-month from each of the five Banner MD Anderson facilities. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 13, 2020 Category: Radiology Authors: Shailja Patel, Steven Sutlief, Keith Dennis, Simul Parikh, Lehendrick Turner Tags: 2020 Student Writing Competition - 1st Place Source Type: research

Hyper-dense foreign bodies found in the bowel during IGRT following brachytherapy
A 28-year-old female with locally advanced adenocarcinoma of the cervix was undergoing treatment with external beam radiation therapy (EBRT), concurrent chemotherapy and high dose rate brachytherapy (BT). On-board imaging obtained prior to one of her external beam treatments revealed four radiopaque foreign bodies in her abdomen. The patient's treatment was delayed for further work-up of this new finding. Upon further investigation, it was discovered that the patient had recently started taking bismuth subsalicylate tablets (brand name: Pepto-Bismol, Procter& Gamble Co., Cincinnati, OH). (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 6, 2020 Category: Radiology Authors: Irena Dragojevi ć, Kelly Kisling, Daniel Scanderbeg, Gina Mansy Source Type: research

Feasibility of hippocampal avoidance whole brain radiation in patients with hippocampal involvement: Data from a prospective study
Among patients with brain metastases, hippocampal avoidance whole brain radiation (HA-WBRT) preserves neurocognitive function relative to conventional WBRT but the feasibility of hippocampal sparing in patients with metastases in/near the hippocampus is unknown. We identified the incidence of hippocampal/perihippocampal metastases and evaluated the feasibility of HA-WBRT in such patients. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 6, 2020 Category: Radiology Authors: Grace Lee, Luke Besse, Nayan Lamba, Cindy Hancox, Iquan Usta, Fred Hacker, Paul Catalano, Paul D. Brown, Shyam Tanguturi, Itai Pashtan, John Phillips, Daphne Haas-Kogan, Brian Alexander, Daniel Cagney, Ayal Aizer Source Type: research

4D in vivo dose verification for real-time tumor tracking treatments using EPID dosimetry
The use of sophisticated techniques such as gating and tracking treatments requires additional quality assurance to mitigate increased patient risks. To address this need, we have developed and validated an in vivo method of dose delivery verification for real-time aperture tracking techniques, using an electronic portal imaging device (EPID)-based, on-treatment patient dose reconstruction and a dynamic anthropomorphic phantom. Using 4DCT scan of the phantom, ten individual treatment plans were created, 1 for each of the 10 separate phases of the respiratory cycle. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 6, 2020 Category: Radiology Authors: Sajjad Aftabi, David Sasaki, Timothy VanBeek, Stephen Pistorius, Boyd McCurdy Source Type: research

Application of hypoglossal nerve constraint in definitive radiotherapy for nasopharyngeal carcinoma: A dosimetric feasibility study
Purpose: Radiation-induced hypoglossal nerve palsy is an infrequent but debilitating late complication after definitive radiotherapy for head and neck cancers. D1cc (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 3, 2020 Category: Radiology Authors: James C.H. Chow, Jeffrey C.F. Lui, Kwok-Hung Au, Ka-Man Cheung, Roger K.C. Ngan, Alex K.C. Leung, Kenneth W.S. Li, Jeffrey C.H. Chan, Kam-Hung Wong, Francis K.H. Lee Source Type: research

Rationale for Using a C-Arm Fluoroscope to Deliver a Kilovoltage Radiotherapy Treatment to COVID-19 Patients
In 2013, Calabrese et al. described the effectiveness of early 20th century radiotherapy to treat viral and bacterial pneumonia patients, citing a cure rate of ∼80%.1 These were single fraction treatments of 30-100 cGy dose delivered with 100-200 kVp x-rays. These treatments stopped in the 1940s due to the availability of antibiotics and steroids, but in light of the lack of effective treatment options for COVID-19, radiotherapy could offer a viable and immediate option2,3 until a more effective cure becomes available. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 24, 2020 Category: Radiology Authors: D. Roa, H. Moyses, S. Leon, B. Hamrick, G. Sarria, T. Tajima, A. Necas, C. Guzman, O. Paucar, A. Gonzales, R. Challco, M. Montoya, Z. Arqque, A. Gonzales, J. Hernandez Source Type: research

Evaluation of a new GPU-enabled VMAT multi-criteria optimisation plan generation algorithm
To evaluate the new Varian, graphical processing unit (GPU)-enabled, volumetric-modulated arc therapy (VMAT) multi-criteria optimisation (MCO) tool for both its dosimetric accuracy and calculation time. This is a new capability within V16.0 and greater of the Varian Eclipse treatment planning system that allows VMAT optimisation and dose calculation using the GPU (termed GPU-VMAT). In versions prior to V16.0 VMAT multi-criteria optimisation calculations were only possible using central processing unit (CPU) (termed CPU-VMAT) and Hybrid-VMAT (H-VMAT). (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 11, 2020 Category: Radiology Authors: Myles Spalding, Anthony Walsh, Trent Aland Source Type: research

A quantitative comparative study of medical dosimetry graduates with and without prior radiation therapy certification
All but a small number of formal medical dosimetry programs require radiation therapy certification for admission. The problem is a lingering perception from the radiation oncology community that medical dosimetry students must have a prior radiation therapy certification and/or experience. There is a paucity of evidence in the literature to support the perception that prior radiation therapy certification equates to better job performance as a medical dosimetrist. The purpose of this quantitative comparative study was to investigate outcomes of medical dosimetry graduates with and without prior radiation therapy certifica...
Source: Medical Dosimetry - July 9, 2020 Category: Radiology Authors: Nishele Lenards Source Type: research

Evaluation of replanning in intensity-modulated proton therapy for oropharyngeal cancer: Factors influencing plan robustness
The head and neck (H&N) region is frequently replanned during intensity-modulated proton therapy (IMPT), but replanning disrupts clinical workflow and presents additional burden on patients. The purpose of this study was to establish a standard treatment planning approach to minimize H&N replanning by identifying a correlation between dosimetric variables and replan frequency. In a retrospective study of 27 bilateral oropharyngeal cancer patients treated with IMPT at a single institution, cases were evaluated using Fisher's exact tests and logistic regression for a significant relationship between replan frequency ...
Source: Medical Dosimetry - July 9, 2020 Category: Radiology Authors: Noelle Deiter, Felicia Chu, Nishele Lenards, Ashley Hunzeker, Karen Lang, Daniel Mundy Source Type: research

Effects of gas-filled temporary breast tissue expanders on radiation dose from modulated rotational photon beams
This study therefore builds on previous investigations of the dosimetric effects of gas-filled TTEs in static photon and electron beams, by examining the effects of these implants on dose distributions from common modulated rotational treatment techniques; volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT). (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 9, 2020 Category: Radiology Authors: Tanya Kairn, Marika Lathouras, Michelle Grogan, Benjamin Green, Steven R. Sylvander, Scott B. Crowe Source Type: research

A format for dosimetry comparison studies
There is no standardized format for presenting and discussing the results of a radiotherapy dosimetry comparison study. The purpose of this report is to describe a format that we have found useful in evaluating plans in our department and in reviewing studies from other groups. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 7, 2020 Category: Radiology Authors: Robert J. Amdur, Roi Dagan, Adam Holtzman, Anamaria R. Yeung, Kathryn E. Hitchcock, William M. Mendenhall Source Type: research

Comparison of conventional and advanced radiotherapy techniques for left-sided breast cancer after breast conserving surgery
This study aims to compare seven WBRT techniques including conventional tangential, field-in-field (FIF), hybrid intensity-modulated radiotherapy (IMRT), IMRT, standard volumetric modulated arc therapy (STD-VMAT), noncoplanar VMAT (NC-VMAT), and multiple arc VMAT (MA-VMAT). Fifteen patients who were previously diagnosed with left-sided early stage breast cancer and treated in our clinic were selected for this study. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 5, 2020 Category: Radiology Authors: Yibo Xie, Daniel Bourgeois, Beibei Guo, Rui Zhang Source Type: research

Optimized stereotactic volumetric modulated arc therapy as an alternative to brachytherapy for vaginal cuff boost. A dosimetric study
We evaluate the role of stereotactic body radiotherapy using volumetric modulated arc therapy (VMAT) technique as an alternative to high-dose rate brachytherapy (HDR-BT) in the treatment of vaginal cuff in postoperative endometrial cancer. CT scans of 8 patients were used in this study. The clinical target volume (CTV) was defined as the 0.5 cm tissue around the applicator (then subtracting the applicator). Total dose was 30Gy delivered in 5 fractions. In HDR-BT, dose was prescribed at a distance of 0.5 cm from the surface applicator. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 18, 2020 Category: Radiology Authors: Savino Cilla, Gabriella Macchia, Giancarlo Mattiucci, Anna Ianiro, Carmela Romano, Milly Buwenge, Luigi Azario, Vincenzo Valentini, Francesco Deodato, Alessio G. Morganti Source Type: research

Flattening filter free beam energy selection and its impact in multitarget intracranial stereotactic radiosurgery treatments
This study aims to present a systematic dosimetric comparison of plan quality between 10 FFF vs 6 FFF beams in intracranial stereotactic radiosurgery (SRS) treatments using volumetric modulated arc therapy (VMAT). The dosimetric evaluation is based on radiation therapy oncology group (RTOG) dose conformity (CIRTOG) and gradient (GIRTOG) indices, and irradiated normal brain tissue volume. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 13, 2020 Category: Radiology Authors: Samir Laoui, Dante E. Roa, Jeffrey Kuo, Maxim Baldytchev, Jonathan Gonzales, Salam Dietrich, Nilam Ramsinghani, Parima Daroui, Hanako Farol Source Type: research

Evaluation of beam-on time and number of breath-holds using a flattening-filter-free beam with the deep inspiration breath-hold method in left-sided breast cancer
We performed a dosimetric study to evaluate the benefits of using a flattening-filter-free (FFF) beam with the deep inspiration breath-hold (DIBH) method for left-breast cancer. We used data from 30 previous patients with treatment plans that included DIBH for left-breast cancer with a flattened beam. FFF beam plans were calculated from previous treatment plan images and compared to the original plans in terms of monitor units (MU), number of segments, beam-on time, and breath-holds. Beam-on time was calculated by adding the traveling time of 1.5 second between segments to the time calculated from the MU and dose rate. (So...
Source: Medical Dosimetry - June 12, 2020 Category: Radiology Authors: Toru Takakura, Satoshi Koubuchi, Aiki Uehara, Ayano Tashima, Tomoyo Hirose, Hiroto Kimura, Seiji Tachiiri, Masahiko Koizumi Source Type: research

Dosimetric and planning efficiency comparison for lung SBRT: CyberKnife vs VMAT vs knowledge-based VMAT
This is the first study that compared treatment plan quality and planning efficiency for lung stereotactic body radiation therapy (SBRT) using CyberKnife (CK) Multiplan vs Varian Eclipse treatment planning systems, including volumetric modulated arc therapy (VMAT) and knowledge-based VMAT (KBP-VMAT). Thirteen lung SBRT patients treated with 50 to 55 Gy in 3 or 5 fractions were retrospectively included in this study. CK plans created with Multiplan V. 4.6.1 using 2 fixed circular cones were previously approved used for treatment. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 9, 2020 Category: Radiology Authors: Suhong Yu, Huijun Xu, Asa Sinclair, Xin Zhang, Ulrich Langner, Kimberley Mak Source Type: research

Dosimetric comparison of inverse and forward planning for Gamma Knife stereotactic radiosurgery of brain metastases
The Leksell GammaPlan (LGP) with an inverse planning (IP) tool has been upgraded to version 11.1 since its launch in 2010. We evaluated its IP planning performance by re-planning 16 targets that had been planned using forward planning (FP). The FP and IP plans were compared. A planning guideline for IP process was developed aiming for an unbiased comparison. Sixteen brain metastases (BMs) without nearby critical structures were included in the study (size> 1 cm for all targets). All prior FP were re-planned in the LGP using IP and maintaining the same beam-on time and coverage. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 6, 2020 Category: Radiology Authors: Qianyi Xu, Dershan Luo, David Mulvihill, Warren Goldman, Alan Turtz, Gregory J. Kubicek Source Type: research

Dosimetric effects of dose calculation grid size on the epidural space dose
Introduction: The epidural disease progression is the most common pattern of failure after spine stereotactic body radiotherapy. The aim of this study was to clarify the effect of the dose calculation grid size (CGS) during volumetric modulated arc therapy planning on the dose to the epidural space target. Materials and Methods: In the planning, the volume obtained by subtracting the planning organ at risk volume (PRV) of the spinal cord and/or cauda equina from the planning target volume (PTV) was defined as the PTVeval. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 6, 2020 Category: Radiology Authors: Hidetoshi Shimizu, Koji Sasaki, Hiroshi Tanaka, Takahiro Aoyama, Hiroyuki Tachibana, Yutaro Koide, Tohru Iwata, Tomoki Kitagawa, Takeshi Kodaira Tags: Research Article Source Type: research

A retrospective evaluation of mixed energy volumetric modulated arc therapy for anal cancers with lymph node involvement
Applying dual, or mixed photon energies during radiation therapy is a common practice in 3-dimensional conformal radiation therapy (3D-CRT). Mixed photon energies are used to provide uniform dose coverage to a planning target volume (PTV) that ranges in depth from the skin surface. Though the application of mixed photon energies in 3D-CRT was once the convention for treating anal cancers with lymph node involvement (AC-LNI), the advantages offered by volumetric modulated arc therapy (VMAT) prove to be the optimal form of therapy for AC-LNI. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 6, 2020 Category: Radiology Authors: Mikayla Eskens, Helen Nguyen, William Deere, Nishele Lenards, Ashley Hunzeker, Matt Tobler Source Type: research

OAR sparing 3D radiotherapy planning supported by fMRI brain mapping investigations
The human brain as an organ has numerous functions; some of them can be visualized by functional imaging techniques (e.g., functional MRI [fMRI] or positron emission tomography). The localization of the appropriate activity clusters requires sophisticated instrumentation and complex measuring protocol. As the inclusion of the activation pattern in modern self-tailored 3D based radiotherapy has notable advantages, this method is applied frequently. Unfortunately, no standardized method has been published yet for the integration of the fMRI data into the planning process and the detailed description of the individual applica...
Source: Medical Dosimetry - June 2, 2020 Category: Radiology Authors: G ábor Opposits, Csaba Aranyi, Csaba Glavák, Zsolt Cselik, Lajos Trón, Dávid Sipos, Janaki Hadjiev, Ervin Berényi, Imre Repa, Miklós Emri, Árpád Kovács Source Type: research

Robust treatment planning in whole pelvis pencil beam scanning proton therapy for prostate cancer
Whole-pelvis pencil beam scanning (PBS) proton therapy is utilized in both the intact and post-operative settings in patients with prostate cancer. As whole pelvis prostate radiotherapy has traditionally been delivered with standard photon beams, limited evidence and technical descriptions have been reported regarding the use of proton therapy. Here we present two robust three-field treatment planning approaches utilized to maximize target coverage in the presence of anatomic and delivery uncertainties. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 25, 2020 Category: Radiology Authors: Anish A. Butala, W. Scott Ingram, Shannon E. O'Reilly, Brett Hartl, Ali Kassaee, Curtiland Deville, Neha Vapiwala Source Type: research

Clinical evaluation of photon optimizer (PO) MLC algorithm for stereotactic, single-dose of VMAT lung SBRT
This report quantifies and compares the dosimetry and treatment delivery parameters of PO vs its predecessor progressive resolution optimizer (PRO) algorithm for a single-dose of volumetric modulated arc therapy (VMAT) lung stereotactic body radiation therapy (SBRT). Clinical SBRT treatment plans for 12 early-stage non –small-cell lung cancer patients receiving 30 Gy in 1 fraction using PRO-VMAT were re-optimized using the PO-VMAT MLC algorithm with identical planning parameters and objectives. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 18, 2020 Category: Radiology Authors: Justin Visak, Ronald C McGarry, Damodar Pokhrel Source Type: research

The degree of translational and rotational movement of implanted pacemakers and cardioverter-defibrillators on coronal plane images in patients treated with radiotherapy for lung malignancy
Malfunction of both implantable cardiac pacemakers and cardioverter-defibrillators as a result of exposure to therapeutic radiation is a known risk in radiation therapy. Although guidelines are available to minimize this risk for low energy beams, the guidelines rely on the estimated doses of ionizing radiation received by the device. Implicit in this calculation is that there is minimal day-to-day movement in the position of the device. However, with the exception of the leads in some cases, the devices are not intentionally sewn to the surrounding tissue but simply placed in a pocket in the prepectoral fascial compartmen...
Source: Medical Dosimetry - May 3, 2020 Category: Radiology Authors: Loukas A. Georgiou Source Type: research

Dosimetric and clinical advantages of adapting the DIBH technique to hybrid solitary dynamic portal radiotherapy for left-sided chest-wall plus regional nodal irradiation
To evaluate the dosimetric and clinical advantages of using deep-inspiration breath-hold (DIBH) technique in hybrid solitary dynamic portal radiotherapy (hSDPRT) for left-sided chest-wall plus regional nodal irradiation and to demonstrate a simplified strategy for preclinical commissioning and calibration of DIBH-gating technique. Fifteen patients with left-sided breast cancer who underwent postmastectomy radiotherapy using hSDPRT were retrospectively evaluated. Two sets of planning-CT images were acquired for each patient, one with free/normal breathing and the other with DIBH. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 2, 2020 Category: Radiology Authors: Kather Mohamathu Rafic, Solomon Patricia, Balasingh Timothy Peace, Christopher J. Sujith, Backianathan Selvamani, Paul B. Ravindran Source Type: research